Typically, creating new user interfaces for software applications or online publishing requires new source code to be written by software developers. In a software application, for example, a user interface would be designed, and a trained developer would write source code that renders user interface objects on a display and allows user interaction according to the intended functionality. In online publishing of web pages, when a web page is accessed, a user interface may be written in a static markup language or a dynamic language that renders markup language. In either case, source code is written that causes the user interface to be rendered and behave in the desired manner.
Writing source code is time consuming and expensive due to the need to use highly-skilled programmers. Updating source code is also a challenge, since the code can be lengthy and difficult for even skilled programmers to interpret.